1. Field of the Invention
The invention relates to memories, and more particularly to flash memory device.
2. Description of the Related Art
A flash memory is a non-volatile memory that can be electrically erased and reprogrammed. Flash memories are primarily used in memory cards and USB flash drives for general storage and transfer of data between computers and other digital products. A flash memory costs far less than an EEPROM and therefore has become a dominant memory device applied in electronic products. Examples of applications include Personal Digital Assistants (PDA) and laptop computers, digital audio players, digital cameras and mobile phones.
A data storage device comprising a flash memory that stores data for a host is referred to as a flash storage device, or a memory card. The flash storage device is coupled to a host. The host may be a computer, a digital camera, or an MP3 player. When the host wants to access the flash memory, the host sends commands to the flash storage device. A controller of the flash storage device then accesses the flash memory according to the commands sent by the host.
In some applications, the host may request the flash storage device to perform specialized operations which can only be started by a specific method. For example, a manufacturer of flash storage devices may perform self-test operations of the flash storage devices for verifying the functions of the flash storage devices. Accordingly, the self-test operation of the flash storage devices should not be performed by general users. Additionally, a self-repair operation may be required by a manufacturer of flash storage devices for faulty flash storage devices. Similarly, the self-repair operation should not be performed by general users. To perform the specialized operations, the host must perform the specialized operations of the flash storage devices by a specific method, thus preventing the specialized operations from being performed by general users. A method for transmitting specialized commands to a flash storage device is therefore required.